On 31 March 2013, Chinese authorities reported the isolation of an avian influenza A(H7N9) virus from human patients in the People’s Republic of China, the first occurrence of this virus subtype in humans.  This virus appears to cause few to no clinical signs in infected domestic chickens, and is thus classified as a LPAI virus.  To date this particular H7N9 virus has not been isolated in any wild bird species, although there has been one isolate taken from a pigeon classified as “wild.”  Since pigeons live in close contact with humans they can be considered “urban” or peridomestic fauna and do not necessarily reflect the state of true wildlife.

It is important to note that at this stage wild birds have not been identified to play any role in the spread of this virus. The Task Force considers that wild birds are unlikely to be a major concern for the spread of this virus in the coming weeks. While there is a risk that migratory birds could spread the disease to new areas at some stage, at the moment other pathways for infection such as from live poultry markets or domestic poultry movements are of a higher priority for attention.

To read the full statement of the Scientific Task Force on Avian Influenza and Wild Birds, please click here.

The Scientific Task Force on Wildlife and Ecosystem Health recently supported two poster presentations at the first joint Wildlife Disease Association and European Wildlife Disease Association conference in Lyon, France between 23-27 July 2012.  The conference was attended by over 500 people from all over the world, including some Task Force members.

The first poster was a general overview poster for the Task Force highlighting our areas of interest and upcoming project work.   A wide range of wildlife professionals including veterinarians, ecologists, and epidemiologists indicated their interest in participating in the Task Force.

The second poster was created through a collaboration by Core Affiliates, namely the Convention on Biological Diversity, the Food and Agriculture Organization of the United Nations, Wildfowl and Wetlands Trust, and the United Nations Environment Program Convention on Migratory Species.  The poster, entitled Impacts of Farming Intensification on Wildlife and Ecosystem Health, covered both negative and positive impacts of farming intensification, outlined general ways to intensify farming in a sustainable way, and provided two case studies.  The first case study discussed the impacts of farming intensification and disease emergence, using the example of Severe Acute Respiratory Syndrome (SARS) and intense farming and marketing of live animals.  The second case study highlights an example of successful farming intensification by diversifying an operation to include both pig production and corn production.

Potential positive outcomes of farming intensification:

• Decreased cost of animal products

• Increased availability of animals and animal products (increased outputs)

• Increased trade through the region and between rural and urban areas

• Improved food security

Potential negative outcomes of farming intensification:

• Decreased genetic diversity of livestock produced

• Increased pathogen transmission due to higher densities of livestock and increased contacts among livestock, humans, and wildlife

• Immune compromised livestock populations and increased susceptibility to  pathogens

• Habitat loss and environmental degradation due to farming development, expansion, and point source run-off and diffuse pollution

• Changes in biodiversity within agro-ecological systems

• Selection pressure for  pathogen strains adapted to survive in modified agricultural environments and changes in pathogenicity (ie SARS, H5N1 HPAI)

Important Aspects of Sustainable Livestock Farming Intensification:

1. Biodiversity and Ecosystem Services:  Using integrated pest management or incorporating natural areas into farmed land areas to preserve the local ecosystem.
2. Conservation-Minded Agricultural Practices:  Utilizing multipurpose crops and performing crop rotation to prevent agricultural runoff and support livestock feed
3. Integrated Pest Management:  Alternatives to pesticides, or maintaining a separation between livestock and wildlife whenever possible to prevent transmission of pathogens or vectors (eg ticks) between species.
4. Integrated Plant Nutrient Management:  Monitor the health of soil and water and implement mitigation measures such as treatment wetland systems for dealing with waste.
5. Integrated Weed Management:  Crop rotation, maintain livestock in coordination with plant cropping to reduce use of herbicides and aid in weed management.
6. Soil Retention, Quality and Integrity: Maintain adequate nutrients in the soil, ie diversifying the farm or reducing grazing density.

While there are a variety of negative impacts that can occur through the intensification of farming processes, we must think outside the box to come up with sustainable ways to increase our outputs in order to feed a hungry world.  If we are not careful in how we intensify, we increase the risks of emerging zoonoses through placing large numbers of stressed and potentially immunosuppressed animals into close contact.  Utilizing the methods outlined above is a great start for sustainable farming intensification.

Find the full story on the FAO page: http://www.fao.org/ag/againfo/home/en/news_archive/2012_Impacts_of_farming_intensification_on_wildlife.html

Check out these links below for more information on farming intensification, the Wildlife Disease Association, and SARs:

1. Integrated Crop Management (FAO):  http://www.fao.org/docrep/012/i1650e/i1650e00.pdf
2. Sustainable Crop Production Intensification (FAO):  http://www.fao.org/agriculture/crops/core-themes/theme/spi/en/
3. Ethics of Sustainable Agricultural Intensification (FAO ):  ftp://ftp.fao.org/docrep/fao/007/j0902e/j0902e00.pdf
4. Avian Influenza (FAO):  http://www.fao.org/avianflu/en/index.html
5. Biosecurity for Highly Pathogenic Avian Influenza (FAO): ftp://ftp.fao.org/docrep/fao/011/i0359e/i0359e00.pdf
6. SARS (WHO):  http://www.who.int/csr/sars/en/
7. Wildlife Disease Association: http://www.wildlifedisease.org/

But what about the many other roles that bats play? Bats maintain ecosystems through pollination, insect control, and other useful ecosystem services.  Insectivorous bats are the main predators for nocturnal insects providing a significant reduction in crop pests worldwide.  It has been estimated that bats contribute millions of dollars to the agriculture industry through pest reduction.  In fact, they offer valuable pest control services, estimated that they save American farmers between US$3.7 billion and US$54 billion a year through pest control. Fruit bats are responsible for a wide variety of plant pollination and seed dispersal necessary for healthy ecosystems and food security.   In some regions of the world, people rely on bats for their livelihoods through the collection of bat feces, called guano, or even as a source of food.

FAO published a manual in November 2011 entitled “Investigating the Role of Bats in Emerging Zoonoses: Balancing Ecology, Conservation and Public Health Interest” that explores bat ecology and their role in emerging infectious diseases while highlighting the important role they play in maintaining ecosystems that support human, plant and animal life. The manual targets epidemiologists, natural resource professionals, veterinarians, among others who increasingly interact with bats.  As livestock and human populations expand and encroach into wildlife habitats we see an increasing amount of zoonotic diseases spread to livestock and humans, some with a reservoir in bat populations.

While bats can pose a threat to human and livestock health, they are also facing a variety of threats of their own.  Bats in the USA are facing a grave threat, White Nose Syndrome, a fungal disease caused by Geomyces destructans, which is decimating bat populations in North America.  The symptoms were first identified in bats by cavers during the winter of 2006, but it was not until October 2011 that the causative agent was confirmed.  To date the fungus has caused the death of over 5.5 million bats across North America, and was most recently identified in Little Grey Bats, an endangered species.  By the end of February 2012 the fungal disease was identified in 16 Northeastern states in the US and in Southern Canada. Clinical signs in bats include waking early from hibernation, white fungal growth on nose, wings, ears, and tail. The site of the highest concentration of fungal infection is actually located in the wings of the bat, although the disease does show the characteristic white cotton-like growth on the nose.  The pathophysiology leading to the death of the bats is still unknown.  Unchecked, this disease could lead to the eventual regional extinction of some species of bats.

For More Information on Bats, White Nose Syndrome, or the FAO Bat Manual please see the following:

http://www.caves.org/WNS/WNS%20Kunz%20April%205%20%202011.pdf

http://blogs.usda.gov/2012/06/08/florida-bat-survey-tests-for-white-nose-syndrome-and-bat-health/

http://www.fws.gov/whitenosesyndrome/

http://www.new-ag.info/en/focus/focusItem.php?a=2399

http://www.fao.org/docrep/014/i2407e/i2407e00.pdf